Isospin asymmetric matter in a nonlocal chiral quark model

TL;DR

This paper investigates the phase structure of strongly interacting matter with isospin asymmetry using a nonlocal PNJL model, revealing an isospin symmetry broken phase and aligning well with lattice QCD results.

Contribution

It introduces a nonlocal PNJL model to study isospin asymmetric matter, providing improved phase diagram predictions consistent with lattice QCD.

Findings

Identification of an isospin symmetry broken phase at high isospin chemical potential

Phase diagram aligns better with lattice QCD than local models

Critical temperature for phase transition around 170 MeV

Abstract

We analyze the features of strongly interacting matter in the presence of nonzero isospin chemical potential $\mu_I$, within a nonlocal two-flavor Polyakov-Nambu-Jona-Lasinio (PNJL) model. For a system at finite temperature $T$, we describe the behavior of various thermodynamic quantities and study the phase diagram in the $\mu_I - T$ plane. In particular, it is found that for values of $\mu_I$ larger than the pion mass and temperatures lower than a critical value of about 170 MeV the system lies in an isospin symmetry broken phase signaled by the presence of a nonzero pion condensate. Our results for the phase diagram are found to be in better agreement with those arising from lattice QCD calculations, as compared to the predictions from other theoretical approaches like the local PNJL model.